Means for marking granular, lumpy, and dusty commodities



Patented Jan. 9, I945 MEANS FOR MARKING GRANULAR, LUMPY, AND DUSTYCOMIWODITIES Raymond E. Miskelly, Plymouth, Masa, assignor to PlymouthCordage Company, Plymouth,

Mass., a corporation of Massachusetts No Drawing. Application August 1,1941,

Serial No. 405,075

9 Claims.

This invention relates to means for marking granulanlumpy and dustycommodities.

The invention is suitable for marking bituminous coal and othercarbonaceous solid fuel, as coke, anthracite and briquettes; alsocommodities of a dlfierent nature, for example, crushed ore, or stone,or grain, or seed; and any other whose physical structure and commercialstatus are such as to warrant the use of the mark herein described fordistinguishing the origin, the ownership, the kind, grade or quality,the age, or some other characteristic of the particular aggregation ofnodular, fragmented or comminuted particles to which the mark isapplied.

It is one object of the invention to provide a mark which will live as amark as long as the commodity lives to which it is applied, yet whichneed not be a thing that interferes with the normal appearance of thecommodity, or its utility, as by discoloring, defacing or adulteratingit. As applied to such a friable commodity as'coal, this stated objectmeans that the mark is to survive the normal tumbling, crushing,abrasion, oxidation and other experiences which coal undergoes duringshipment, handling and storage with incidental lapse of time, exposureto air and to weather; and with superficial flaking and fragmentationsuch as occurs as coal dries.

Toward these ends the invention provides a dispersion of a finelydivided substance whose particles constitute a mark in that they shineout as bright points of light, especially in a dim light or darkness.

Dispersed in the commodity which they mark, they do not change theappearance of that commodity as seen in ordinary light. And they may bethemselves substantially invisible. But when ultraviolet rays are thrownupon a mass of that commodity they glow with distinctive brilliance.

In dusty commodities, as bituminous coal, the marking particles may beindependent of the coal lumps; that is, they do not need lumps toreceive and support them, because they may be particles of dust mixed inthe coal dust. In a commodity having but little dust, as briquettes, oranthracite, where the lumps or other units are all so large v that amarking dust might settle and fail to maintain its dispersion, themarking particles may be held on the units of the marked commodity. Ineither case the mark is a dispersion of particles of an extraneoussubstance such that the par, ticlesfluoresce so as to glow brightly inthe dark, under ultraviolet rays: and these particles may be carried bydispersed particles of a second extraneous substance. In optimum formfor bituproducts of a suitable dye, are adsorbed on or' otherwisecarried by the second mentioned dispersed extraneous substance, whichmay be of cellulosic nature, as wood or cotton. Or, the carrierparticles may be a colorless lacquer, or may be of other substance, as,for example, an inorganic powder, or fragments of wool. It is notnecessary thatthe fluorescing particles be visible in ordinary lightafter being dispersed. And the second mentioned extraneous substance,the carrier, may be one that ultimately becomes unnoticeable in thecommodity, as, for example, either by itself adhering on the surface ofa lump without showing color, or by reason of adhesion of coal dustto'its own surface.

It has been previously proposed to mark coal by coating the lumps withsome color or material so as to, change the appearance of the coal, orby distributing manufactured geometrical shapes of wood. The success ofthe coloring depends upon there being lumps of sufl'lcientsize, or elserequires much color material. Geometrical shapes are expensive to make.And neither system is applicable to grain or seed. The present inventioncan be used with any of such commodities; its shapes are not geometricalbut may be fragments of waste materlalinexpensive, and. yet ofdistinctive type; and it is not dependent on there being lumps in thecommodity, but it can be effective in dust. However, the marker can beheld on lumps, either by use of an adhesive, or by adsorptive afflmty ofthe carrier particles, or in some cases by aflinity of the markingparticles alone.

One instance of a carrier made of material extraneous to the commodityis finely divided wood, such as sawdust, or wood flour, or choppedparticles of excelsior. The selection of marking material can be madeamong substances for which wood has a strong adsorbent aflinity withincidental propertyof fluorescence. Examples are found in dyes. Theconcentration of fluorescent power on each particle 'of wood may be sostrong that whatever of coal dust gathers on the parti-cle does notocclude all the light that shines forth when ultraviolet rays areapplied.

If the commodity which is to be marked has sizable lumps or nodules,such as the customary minous coal the mark has the property that theactivating particles, which may be particles or lumps of :bituminouscoal, or those found in anthracite, or coke, or briquettes, a substanceto fluoresce for the marking may be selectedfrom among those which arefluorescent in powder form and for which the marked commodity has aretentiveaftlnity, for example, as coal has for commercial anthracene.In such case the marker may be dusted over the commodity, for itsparticles to cling on the lumps or nodules by mutual afllnity andsurface adhesion. When finely dispersed in small percentage in coal,these particles will be substantially invisible in ordinary light, yetwill shine out in brilliance under ultraviolet rays in which the coal isdark. If the marking powder which it is desired to employ is one forwhich the retentive affinity of the commodity is low, a liquid adhesivecarrier for holding the particles of marker on the lumps may beemployed, as starch or gum arabic, or an insoluble glue as casein. Anexample of a marking powder, whose density makes it desirable that anadhesive be employed for holding it in dispersion, is any fiuorescingvariety of zinc sulfide.

When a liquid is employed to carry the marker, the spraying of theliquid upon a thin passing stream of the commodity, as upon coaldescending a chute, disperses globules. These adhere, and, upon drying,the marking material they ca y is fixed in its dispersion through themass of the commodity. An example of a liquid carrier, for which thesolids of a lump commodity have high dsorptive or other retentivealfinity, is lacqu r. Applied to coal, their mutuality of afflnityspreads the globules into films. They are detectible only upon veryclose inspection of the coal. The usual flaking which occurs with thedrying of the coal does not prevent any particle, whether on a lump orin the dust, from glowing in the darkness of ultraviolet rays.

The color of fluorescent glow may be pre-selected by observing the colorin which the energy, applied through ultraviolet rays, is re-emitted bythe particular kind of material. A diversity of marks, among whichselection can be made, can also be 'had by predetermining variousdensities of dispersion, for applying the carrier particles throughoutthe coal which they are to mark.

One way to do this is to combine in a mass the output of a chute whoseproduct is marked with that of one or more whose output is not marked.Diversity can also be had by choosing the carrier particles frommaterials having diverse characteristics, the peculiarities whichcharacterize any particular mark being discernible by' examination ofthe individual particle, perhaps under the microscope, after such aparticle has been found in the coal by its emission of light. Anexample, in wood, is the diversity of characteristic shapes which existsbetween shreds of sawdust and choppings of excelsior; or between sawdustof one particular kind of wood and the dust of another particular kindof wood having different natural cell structure. The invention thusserves an important industrial need, in that it enlarges the field fromwhich marks are available for selection, to distinguish individually theproducts of diflerent mines, ordiflerent companies, or other sources, ascompared with the limitations of choice which are at present imposed bythe smallness of variety available in systems now in use.

It is another feature that the mark of the invention can be utilizedwithout its introducing anything deleterious. Wood fragments are alwayscombustible with the coal; and so are lacquers. In the case of grain,wood fragments will be removed with the hulls in the operation ofmilling. In either case the quantity introduced is not sufficient toconstitute an adulteration. since the dispersal of only a pound or so ofsawdust through each tonof coal gives an efl'ective frequency of pointsof light.

It is convenient herein to use the term "particles in referring to thefluorescent substance, i. e.. the marking material, which activates" thebase material whose small solids or liquid globules are also "particles"that carry the marking material. If the carrier is a soluble liquid orsolid, this carrier may be the solute in a volatile solvent by which thedispersal is effected, but from which the solvent will later evaporate,leaving the carrier holding the mark in the dispersed relation. Thus anitrocellulose lacquer, or a less inflammable lacquer as celluloseacetate, or one that is less expensive as shellac, may be a base to beactivated into capacity for fluorescing by carrying a suitable dye; andmay itself be dissolved in a volatile solvent, and in that solvent besprayed in globular particles which become dispersed throughout the massof the granular commodity which they ultimately mark. And it isconvenient to use the term granular to signify all the various kinds andgrades of granular, nodular, lumpy, dusty, or powdery commodities.

For practicing the invention by admixture of particles of wood or thelike the said particles may be of any predetermined shape, definite ornondescript; but economy will dictate their being made in quantity'bymechanism. Hence those made by any particular kind of operation, as bysawing, will have certain characteristics in common, and thesecharacteristics will be identifiable by ordinary inspection or test. Fora particular markin the base material may be selected wholly of a singlevariety; or may be a selected mixture of varieties. The rang availablefor selection of this base material is infinite in number of varities.Economical and convenient base material is found in the sawdust which isa waste product in lumber mills; but other bits of wood are available,or may be produced by cutting or chipping processes; and other durablematerials are available, whose nature is cellulosic so that they areadsorbent of the activating material, among which are paper, paper pulp,rayon and cottonwhich can be used either as cut fibre or short lengthsof yarn or thread; also bast fibres, as those of flax, jute and othergrasses; and also leaf fibres as those of sisal; and products ofnumerous other plants, also animal products, as Wool, hair, silkany ofwhich can be fragmented to desired specified dimensions-as well assynthetic products of all sorts.

A preliminary bleaching of the base material, as with sodiumhydrosulfite, sometimes helps the brilliance with which the particlesfiuoresee after the activating material has been applied. This isespecially true of resinous wood such as pine; while fragments of otherwoods, as of some poplar, are satisfactory without it.

The substance which is to constitute the active marking particles is tobe selected among those which fluoresce brightly when dispersed in thecoal or other commodity which is to be marked. Against a blackbackground of coal, a dull fluorescence is not a satisfactory mark, ascompared with one that shines forth brilliantly. Selection can be madeonly on a basis of discovery by experiments with the substance proposed,for some substances do not fiuoresce brightly, although other similarsubstances do. Some are fluorescent in one solution and not in anothersolution. Some may be normally fluorescent, and yet not appear so whendispersed in coal; and, by contrast, Diazo Fast Yellow 2G does notfiuoresce in water solution, yet does in solid form; and does so when itis carried on cellulosic material, as wood sawdust. Some are fluorescentwhen. in a certain solvent, but when dyed on cellulose are not so; andcertain substances are found to fluoresce satisfactorily when taken intheir commercial or technical form, as'available in the market, but notwhen chemically pure. The active particles herein described thereforeare those'wh'ich in a Practical sense slow luminously in their sur- 6roundings when exposed to ultraviolet rays, the mark bein best seen whenthe main body of the mass which is'marked is examined in shadow or inlight which provides onlypoor visibility.

Numerous substances exist which meet the requirements for the marker ofthe invention. I

have found that activating matrlalssuitable for application to a solidbase such as sawdust or other cellulosic material by usual dyeingmethods include the following recognized in the trade as follows:

Color and reaction Color of activated ma- Dye index terial (carrier)number under ultravblet rays Acriilavine "J Yellow.v Thiol'lavine 'lG Ex#815. Yellou: to greenish ye w. Eoe OI flGB-WIL- Red. 1 blue 6 W93.Yellow Plies blue 2101.. #793 Orange Erie vine S i816 Yellow 'lhhlineBed RXX I226 Nacclanlink G Nnm Orange Celliton Brilliant Yellow FF ..oYellow Brillhnt Dianil Green 0.. 0 Green. Caleocid Fluorescent BlueG1,--. n Blue. Alcoool Golden-Yellow IGK do Olive Rhodamine B Extra.#749 Orange. Primuline I812 Yellow. Auramine O 1665 D o. Diaeo FastYellow 2G Bluish-white. R 6GDN #752. Orange. Pyronine... #741. Blue.Antbncene (Tech) 1% sol. in Yellowish-greenr benzene (base for dyes).

Among dyes heaving a community of physical and chemical characteristicssuch that each might be expected to meet the requirements of w theinvention, I have found many inoperative but have demonstrated that theforegoing are operative. p

In each case in which there are corresponding dyes of the same colorindex numberbut produced by another maker and called by a somewhatdiflerent name, the result and. behaviour have been found similar tothose above listed; and these are considered equivalents. The ColorIndex numbers are those given in the Color In-. .50

dex of the Society of Dyers and Colorists, edited by I". M. Rowe.

The foregoing table represents reaction of acrial treated; ratio ofmaterial to water 1:30; dyed at 180 F. for 15 minutes, except Auramine Oat 140.

In the foregoing list, primuline is most satisdyes, having names i5wood. Care should'be. taken that the wood particles are loose fromeachother, so that when applied to the granular commodity they caneasily become widely dispersed through it. Ordinarily the drying wili\ut them. into condition for this, but if necessary e mass of activatedsawdust or other fragmen layer of coal which is sliding and tumblingdownward as a stream along an inclined chute.

If theactivated particles are'to be dispersed in a liquid, as in asolution of lacquer or a resin, natural or synthetic, in a volatilesolvent, the activator may be applied to a body of the liquid by amixing process, producing a suspension or a solution of the activator inthe carrier, or, in the case of lacquer, an actual dyeing'of thelacquer; and a solution of the carrier in the volatile solvent; and thenthe liquid may be sprayed upon such a thin tumbling layer of thecommodity.

The following are examples of dyes for treating a liquid base such aslacquer or shellac in the practice of the invention so that when sprayedon the commodity, as coal, the reaction of the deposited particles underultraviolet rays will be as indicated, demonstrated operative amongnumerous similar that are found not satisfactory:

Color E Reaction In some cases, in which anthracene is an example, afluorescent powdered solid has retentive aflinity for coal, and may beapplied to this commodity by being merely dusted over a passing streamof the commodity. But fluorescent pigment can be had, such asfluorescent zinc sulfide, or other powder which is independentlyfluorescent, as ground fluorescent lake, dispersed and held on'granuleof commodity by an adhesive. If the dispersion of particles shouldchance factory and is the substance preferred for actito be discerniblein ordinary light, no harm is vating sawdust for yellow fluorescence. Incase the sawdust is of wood whose results are improved with apreliminary bleaching, primuline is notaifected by a hydrosulfltebleach, and the bleaching and dyeing can take place in the same 05\path, with a saving in cost.

A preferred way to apply the activating material to a, base such assawdust which will become its carrier is either by spraying thefluorescent activating material in volatile solution over a mass of thesawdust, or by immersing the sawdust in such a solution, so that thedust becomes done, but the marking effect is that which is seen underultraviolet rays. An example of such a lake is one made from aluminumsulfate, sodium silicate and a suitable yellow dye such as primuline.For holding on the commodity a pigment which does not naturally adhere,as for holding anthracene on briquettes or anthracite, or for holding alake, starch or gum arabic can be applied in liquid form to thecommodity with or previous to the application of the particles that areto constitute the mark.

The coal or other commodity thus marked may then go along'in its usualcourse in commerce, carrying with it the'mark. If the mark and the138131161 are selected of inconspicuous materials.

material may be agitated or beaten to. make its particles be separatefrom v or if they pick up coal dust, the mark will not affect theappearance of the coal, and the presence of the mark may be notnoticeable. But the mark will be discernible at any time, andpreeminently so in darkness, by a casting of ultraviolet rays upon asample taken from the mass. Sources of ultraviolet rays are available inpoi-table form, using fllters to eliminate visible light.

The mark thus made can indicate whatever those who use it may elect thatthe mark shall mean. For example, authenticity of the marked coal ashaving come from a particular source can thus be told, ascertained, orverified. If all of the coal produced in a particular locality is thusmarked distinctively, absence of "the mark in a particular body of coalfound in the market will show that the origin of this coal Waselsewhere. Presence of the mark in abnormal scarcity will indicate thatcoal of other origin has been admixed. This provides a safeguard againstunscrupulous dealers, who may introduce coal other than a particularkind ordered; also it provides a means of learning the source, in caseof doubt. The ease and low cost at which the sawdust, or other activatedfragmented base, can be dispersed through the coal at the breaker,prevents the counterfeiting of the mark by anyone who is a mere dealer;for no mere dealer is in position to counterfeit the mark by making agood distribution through his coal, except at a cost which would morethan exhaust all profits he might hope to make by his proposedfraudulent substitution.

The materials for the carrier, and those for the activating, are of suchlow cost, and the cost of applying the activating material to thecommodity is so low, that the retail price of the commodity is notunduly burdened by the applying of the mark. The reaction of the mark toultra violet rays, by shooting forth points of light, is distinctive;and it demonstrates convincingly the authenticity of the body of coal inwhich it is found. This is in contrast to the difliculty sometimesexperienced in distinguishing the mark, if any, under methods of markingwhich rely upon changing the appearance of the coal. Other features ofutility are the ubiquity of these points of light in a mass of coal,viewed in darkness; and the great number of varieties, distinguishablefrom each other, in which the mark of the invention can be practiced oncoal and other commodities without injuring the commodity or addingappreciably to its price.

It is intended that the patent shall cover, by suitable expression inthe appended claims, whatever features of patentable novelty exist inthe invention disclosed.

I claim as my invention:'

1. In combination, bulk coal and an identifying marking materialtherefor, said identifying marking material being combined with anddispersed throughout said bulk coal, said identifying marking materialcomprising a fluorescent substance and a. carrier therefor, said carrierbeing of a kind of material which is extraneous to said coal andconsists of water-insoluble, discrete, solid particles, said fluorescentsubstance and carrier being blended with said bulk coal in such a manneras to be inconspicuous in ordinary light and having the property that intheir dispersion throughout said bulk coal they alter the appearance ofthe bulk coal by fluorescence of the fluorescent substance when the bulkcoal is subjected to ultraviolet rays.

2. The combination as set forth in claim 1 wherein said identifyingmarking material is loosely dispersed throughout to said bulk coal.

3. In combination, bulk coal and an identifying marking materialtherefor, said identifying marking material being combined with anddispersed throughout said coal, said identifying marking materialcomprising a fluorescent substance and a carrier therefor, said carrierbeing in the form of water-insoluble, discrete, solid particles whichare extraneous to both said fluorescent substance and said coal, saidfluorescent substance and carrier being blended with said bulk coal insuch a manner as to be inconspicuous in ordinary light and having theproperty that in their dispersion throughout said bulk coal they alterthe appearance of the bulk coal by fluorescence of the fluorescentsubstance when the bulk coal is subjected to ultraviolet rays.

4. The combination as set forth in claim 1 wherein said carrier for saidfluorescent substance adheres to said coal.

5. In combination, bulk coal and an identifying marking materialtherefor, said identifying marking material being combined with andloosely dispersed throughout said bulk coal, said identifying markingmaterial comprising a fluorescent substance and a carrier therefor, saidcarrier being individual particles of fragmented cellulosic material,said fluorescent substance and said fragmented cellulosic material beingblended with said bulk coal in such a manner as to be inconspicuous inordinary light and having the property that in their dispersionthroughout said as bulk coal they alter the appearance of the bulk coalby fluorescence of the fluorescent substance when said bulk coal issubjected to ultraviolet rays.

6. In combination, bulk coal and an identifying 40 marking materialtherefor, said identifying marking material being combined with andloosely dispersed throughout said bulk coal, said identifying markingmaterial comprising a fluorescent substance and a carrier therefor, saidcarrier com-prising fragmented wood, said fluorescent substance and saidfragmented wood being blended with said bulk coal in such a manner as tobe inconspicuousin ordinary light and having the property that in theirdispersion throughout said bulk coal they alter the appearance of thebulk coal by fluorescence of the fluorescent substance when the bulkcoal is subjected to ultraviolet rays.

7. The combination as set forth in claim 5 wherein the fluorescingsubstance is primuline.

8. In combination, bulk .coal and an identifying marking materialtherefor, said identifying marking material being combined with anddispersed throughout said coal, said identifying marking materialcomprising a fluorescent substance and a carrier therefor, said carriercomprising dried particles of lacquer, said fluorescent substance andsaid individual particles of .lacquer being blended with said bulk coalin such a manner as to be inconspicuous in ordinary light and having theproperty that in their dispersion throughout said bulk coal they alterthe appearance of the bulk coal by fluorescence of the fluorescentsubstance when the bulk coal is subiected to ultraviolet rays.

9. The combination as set forth in claim 8 wherein the carrier isshellac.

' RAYMOND E. MISKEILY.

